1. Field of the Invention
The present invention relates generally to medical devices and methods. More particularly, the present invention relates to medical devices, systems, and methods for determining cardiac performance parameters based on data obtained from an intravascular or intracardiac catheter device.
Intravascular and intraluminal interventions and monitoring have become essential in modem cardiology and other medical fields. Of particular interest to the present invention, a variety of intravascular and intracardiac catheters, implantable sensors, and other devices and systems have been developed for monitoring cardiac performance.
The ability to adequately treat patients suffering from or at risk of cardiovascular diseases can be greatly enhanced by frequent, or real time continuous, monitoring of cardiac performance and function. For example, patients suffering from congestive heart failure could titrate dosages of certain medications if more information were available and information were available more often, relating to cardiac performance and function and how they have responded to drug treatment. Additionally, the need for surgical intervention could also be better assessed if better cardiac performance data were available. For example, it is often difficult to distinguish compromised cardiac valvular function due principally to aortic stenosis or mitral regurgitation from other heart conditions such as myocardial insufficiency that causes reduced pumping ability, especially when moth conditions co-exist.
For these reasons, it would be desirable to provide improved devices, systems, and methods for monitoring cardiac performance and function both in and outside of medical facilities. Such improved devices, systems, and methods should allow for measuring a variety of mechanical, biological, and chemical parameters related to cardiac performance and function and analyzing calculated cardiac performance values based on such measured performance characteristics. Preferably, the devices and apparatus will include one or more intravascular catheters which allow for periodic or continuous collection of in situ cardiac performance data. The systems may then calculate physiodynamic cardiac performance parameters based on the measured internal and external performance data which has been collected. At least some of these objectives will be met by the inventions described hereinafter.
2. Description of the Background Art
Catheters and other intravascular and intracardiac devices for measuring various cardiac, physiological parameters are described in co-pending U.S. patent application Ser. No. 10/734490, entitled “Method and System for Monitoring and Treating Hemodynamic Parameters,” filed on Dec. 11, 2003, and commonly assigned with the present application, the full disclosure of which is hereby incorporated by reference. Other catheters and implantable sensors capable of measuring various physiologic parameters in the heart and/or vasculature are described in U.S. Pat. Nos. 5,814,089; 6,328,699 B1; 6,438,408 B1; U.S. Patent Publication Nos. 2001/0053882 A1; 2001/0047138 A1; 2002/0077568 A1; 2002/0111560 A1; 2002/0151816 A1; 2002/0156417; 2002/0169445; and PCT Publication WO 02/065894 A2. The full disclosures of each of these patents and patent publications are incorporated herein by reference.